The invention relates to a parking brake for a vehicle comprising a brake actuation lever which is arranged in an articulated manner on a lever holder, a coupling unit which tensions a brake cable during the displacement of the brake actuation lever, and a locking device in order to hold the brake actuation lever in a locking position.
Parking brakes are known from practice which are embodied selectively as a foot-operated or as a hand-operated unit for a motor vehicle and which have a brake actuation lever which is arranged in an articulated manner on a lever holder fixed to the body, the brake actuation lever being capable of being fixed to the lever holder in different pull-up positions via a locking device and acting, as a function of its pull-up angle, on a brake cable which is coupled to the brake actuation lever via a coupling unit and which tensions brake shoes in the region of the wheels of the vehicle. The articulated connection between the brake actuation lever and the lever holder takes place in this case via a pin which connects corresponding bores in said parts to one another in a pivotally articulated manner. One disadvantage of such known parking brakes is that the transmission ratio between the pivoting angle of the brake actuation lever and the coupling unit of the brake cable is constant, so that it has already been proposed to integrate into the brake cable assembly tension members which define a transmission ratio. A further disadvantage is that, in the case of a hand-operated parking brake, the ergonomic levers for actuating the brake actuation lever become detectably poorer with an increasingly pulled-up brake actuation lever, so that the necessary moments require a marked increase in force, particularly in the direction of the end of the pivoting range of the brake actuation lever. Even in the case of foot-operated parking brakes, there is the disadvantage that the pedal arranged on the brake actuation lever for the action of force provides, when it pivots about a single joint, a decreasing effective pedal surface which reduces the available loading arm particularly in the range of increasing forces.
DE-A 37 06 545 describes a hand lever device for a motor vehicle, in particular a motorized two-wheeler, in which a grip part of the hand lever is held at least approximately parallel to a grip on the handlebar and has a guide in order to allow an approximately parallel displacement of the grip part. The guide is designed as an articulated mechanism in the manner of a four-bar mechanism or as a double-crank mechanism. A locking possibility is not provided.
DE-C 35 28 568 describes a parking brake device for a motor vehicle, in which a brake actuation lever is arranged in an articulated manner on a lever holder and has a grip which is of essentially convex design and which is arranged transversely to the lever holder, wherein, furthermore, a release device assigned to a locking device and having an actuating knob is provided in the end region of the brake actuation lever.